Radial flow valve assembly

ABSTRACT

The disclosed valve may be configured for use as a pressure relief valve, pressure regulator valve or pressure reducing valve. A pair of opposed valve members defines a radial flow path therebetween which extends from the outer radial peripheries of each valve member to an axial bore formed in one of the valve members. The other valve member comprises a substantially pressure balanced piston, the axial movements of which control flow through the valve. A pilot valve for relieving pressure above the piston has its inlet positioned within a cavity formed on the upper surface of the piston. 
     In a second disclosed valve, a pair of opposed valve members defines a radial flow path therebetween which extends from the outer radial peripheries of each valve member to an axial bore formed in one of the valve members. The other valve member is mounted on a stem having an upper end which is urged upwardly by a spring disposed around the stem. A substantially cylindrical element is threadably engaged in the upper end of a valve body in which the valve members are received and the stem is urged thereagainst. In another embodiment, the stem is fixedly connected to the cylindrical element. Rotational movement of the cylindrical element axially moves the stem thereby controlling flow through the valve.

This is a continuation of application Ser. No. 07/209,421, filed June20, 1988, now U.S. Pat. No. 4,895,342, issued Jan. 23, 1990.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The instant invention relates to flow control valves and moreparticularly to such valves in which fluid flows radially inwardlybetween a pair of seat surfaces and into an orifice communicating withone of the seat surfaces.

2. Description of the Related Art

Valves in which fluid flows radially inwardly between a pair of opposingcircular seat surfaces are known in the art. For example, U.S. Pat. No.3,856,043 to Feild et al pressure responsive fluid valve assembly inwhich such flow occurs. In Feild et al., the opposing valve seats aremounted on a pair of opposing valve members, the first of which is fixedrelative to valve body and the second of which is spring-biased towardthe first. Fluid is provided to the outer peripheries of the workingfaces and flows radially inwardly therebetween and into a bore formed inthe second valve member and communicating with the second valve memberworking face.

The valve assembly of Feild et al. accurately regulates pressure over awide range of relatively low flow rates. However, at higher flow rates,side thrust on the movable (second) valve member, as noted in thepatent, prevents accurate regulation.

Also noted in the patent, the pressure distribution between the workingfaces decreases on an exponential basis from the radially outerperipheries of the working faces toward the orifice which is centered onthe second valve member. This aspect of the disclosed Field et al. valveassembly is not necessarily disadvantageous in connection with thestructure and operation of the device shown in the patent; however, ithas been found to be very disadvantageous in valves which utilizeopposed working faces wherein one of the working faces is mounted on apressure-balanced piston, for example, in a pressure regulating,pressure relief or pressure reducing valve. When the working faces insuch valves operate substantially apart from one another, such apressure-balanced valve does not experience problems; however, as theworking faces approach one another, the pressure between the faces dropsthus causing the valve to slam shut rather than continuing its pressureregulation, relief or reducing function.

SUMMARY OF THE INVENTION

In one aspect, the invention comprises a housing have a pair of valvemembers received therein which include opposed working faces. Inletmeans permits fluid flow to a location adjacent the outer peripheries ofthe working faces. Restriction means disposed between the inlet meansand the outer peripheries of the working faces restricts andsubstantially uniformly distributes the flow of fluid about the outerperipheries of the working faces.

In another aspect of the invention, a taper formed on one of saidworking faces is of a size sufficient to substantially eliminate allpressure decrease between said working faces as said valve membersapproach one another when fluid is flowing therethrough.

It is an object of the instant invention to provide an improved radialflow valve assembly which overcomes the above-enumerated disadvantagesof the prior art.

It is another object of the instant invention to provide such a valveassembly which is capable of accurately controlling flow and pressureover a wide range and at extremely high flows and pressures.

It is still another object of the invention to provide such a valveassembly which is resistant to wear and which produces relatively littlenoise at high flows and pressures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is side elevational view of a first valve constructed inaccordance with the instant invention.

FIG. 2 is a view taken along line 2--2 in FIG. 1.

FIG. 3 is a view taken along line 3--3 in FIG. 2.

FIG. 4 is a view taken along line 4-4 in FIG. 2.

FIG. 5 is a view similar to FIG. 4 with the structure shown in aslightly different configuration from that of FIG. 4.

FIG. 6 is a view taken along line 6--6 in FIG. 2.

FIG. 7 is a schematic cross-sectional view similar to that of FIG. 3showing a first configuration of the valve.

FIG. 8 is a schematic cross-sectional view similar to that of FIG. 3showing a second configuration of the valve.

FIG. 9 is a schematic cross-sectional view similar to that of FIG. 3showing a third configuration of the valve.

FIG. 10 is a schematic cross-sectional view of the valve similar to thatof FIGS. 4, 5, and 6, but with the plug and valve cartridge positonsswitched.

FIG. 11 is a schematic cross-sectional view of the valve in the sameconfiguration as shown in FIGS. 4-6.

FIG. 12 is a side elevational view of a second valve constructed inaccordance with the instant invention.

FIG. 13 is a view taken along line 13--13 in FIG. 12.

FIG. 14 is a view taken along line 14--14 in FIG. 12.

FIG. 15 is a view taken along line 15--15 in FIG. 14.

FIG. 16 is a view taken along line 16--16 in FIG. 14.

FIG. 17 is a cross-sectional view of a third valve constructed inaccordance with the instant invention.

FIG. 18 is a view taken along line 18--18 in FIG. 17.

FIG. 19 is a perspective view of the upper portion of the valve shown inFIG. 17.

FIG. 20 is a partial cross-sectional view of a fourth valve constructedin accordance with the instant invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Turning now to FIGS. 1 and 2, indicated generally at 10 is a valveconstructed in accordance with the instant invention. Valve 10 includesa housing or body 12 made up of an upper portion 14, a middle portion 16and a lower portion 18. Each of the body portions are substantiallycylindrical in shape. However, lower portion 18 includes an opposed pairof flat surfaces, one of which is surface 20, machined thereon to enablethreadably engaging valve 10 with other components as will later be morefully explained. Similarly, middle portion 16 includes an opposed pairof flat surfaces 22, 24 formed thereon for the same purpose. Middleportion 14 includes a pair of opposed cartridge mounting stubs 26, 28formed integrally with the middle portion.

Mounted on stub 26 is a plug 30, such including a plurality of radialbores, two of which are bores 32, 34, formed thereon to facilitatethreading and unthreading plug 30 in stub 26. Plug 30 further includes aplurality of locking screws, one of which is screw 36, receivedtherethrough. Each of the locking screws abuts against the radiallyouter surface (not visible in FIG. 1) of stub 26 thereby preventingrotational movement of plug 30. A cross-sectional view of plug 30 andstub 26 is shown in FIG. 6 and is described in more detail hereinafter.

A cartridge valve assembly 38 is mounted on stub 28. The cartridge valveassembly is also referred to herein as means for variably restrictingflow. Radial bores, two of which are bores 40, 42, are formed onstructure associated with cartridge valve assembly 38 to enablethreadably engaging and disengaging the same. Also forming a part of thecartridge valve assembly is a lock nut 44 which is also referred toherein as fixing means. Cartridge valve assembly 38, stub 28 and relatedstructure are shown in cross-section in two different configurations inFIGS. 4 and 5 and will be described more fully hereinafter.

A plate 46, such being also referred to herein as a housing, is boltedto upper portion 14 of the valve body via five bolts, one of which isbolt 48, disposed about the center of plate 46 as shown. A substantiallycylindrical spring shell 50, such being also referred to herein ascontaining means and as a tubular element, is mounted on top plate 46via five bolts, one of which is bolt 52, which are disposedconcentrically around the center of the spring shell. Mounted on the topof spring shell 50 is an adjustment nut 54, such also being referred toherein as adjustable stop means.

Formed in plate 46 is a port 56 which provides fluid communicationbetween the interior of plate 46 and the exterior thereof in a mannerwhich will be more fully explained hereinafter.

Similar ports 58, 60, 62 are formed in valve body 12 for the samepurpose and will likewise be the subject of more detailed descriptionhereinafter.

Turning now to FIG. 3, structure which has been identified in connectionwith the descriptions of FIGS. 1 and 2 retains the same numeral in FIG.3. It should be noted that ports 56, 58, 60, 62 as shown in FIG. 3 arerotated 90° clockwise (as viewed in FIG. 2) in the view of FIG. 3. Thisreduces the number of drawings required and is for the purpose ofillustration only.

Adjustment nut 54, best viewed in FIGS. 1 and 2, includes a hex-headupper portion and a cylindrical theaded lower portion 66 (in FIGS. 1 and3), such being threadably engaged with threads 68 on the radially innersurface of the upper portion of spring shell 50. An axial bore 70 formedcoaxially with nut 54 receives an upper portion 72 of a valve member 74.

Upper portion 72 is also received within a coaxial bore 76 formed inspring shell 50. Received over upper portion 72 is a biasing means orspring 78, such being disposed between a bearing 80 (which is alsoreferred to herein as bearing means) at the upper end thereof and anupward facing annular shoulder 82 disposed about the circumference ofvalve member 74. Bearing 80 is disposed between the lower surface ofadjustment nut 54 and the upper surface of spring 78. It can be seenthat adjustment nut 54 may be screwed in and out thereby varying theextent to which spring 78 is compressed and accordingly varying thedownward biasing action exerted by the spring on valve member 74.

A threaded radial bore 84 permits fluid communication between theinterior of spring shell 50 and the exterior thereof. As previouslydescribed, spring shell 50 is mounted by bolts (like bolt 52).

Plate 46 is, in turn, secured to upper portion 14 of body 12 via bolts,one of which is bolt 48. Plate 46 includes therein a bore 88 which iscoaxial therewith. A bore 90 is formed through the lowermost portion ofspring shell 50 and is coaxial with bore 88. As can be seen, bore 90 isslightly less in diameter than bore 88 thus forming a downward facingannular shoulder 92 at the top of bore 88. Beneath shoulder 92 an upwardfacing annular shoulder 94 is defined about the circumference of valvemember 74. Sealing means or o-rings 96, 98 are received in annulargrooves about the circumference of the valve member as shown. 0-rings96, 98 sealingly engage between the valve member and bore 88. An annularcavity or groove 100 is defined on the radially inner surface of bore 88about the circumference of the valve member. A radial bore 102 formed inplate 46 communicates at one end with groove 100 and at the other endwith port 56.

A first bore 104, such also being referred to herein as a first boreportion, is coaxial with valve member 74 and communicates with thevalve-member lower end or working face 105. A second bore 106, suchbeing also referred to herein as a second bore portion, enables fluidcommunication with diametrically opposing sides of valve member 74adjacent groove 100. Bores 104, 106 intersect and communicate with oneanother.

The lower part of plate 46 includes a radially outer annular portion108, which is flushly abutted against the upper surface of portion 14 ofthe valve body, an annular middle portion 110, and a circular centralportion 112. A downwardly directed counterbore 114 is formed in portion112 and is coaxial therewith. Counterbore 114 communicates with bore 88and the lower portion of valve member 74 is received therein. A pair ofopposed radial bores 116, 118 are formed in central portion 112 andprovide fluid communication between counterbore 114 and the radiallyouter surface of portion 112. Another pair of opposed radial bores (notvisible in the view of FIG. 3) are found in central portion 112 ninetydegrees from bores 116, 118.

A valve seat 120 is mounted on portion 112 via screws (one of which isscrew 121 in FIGS. 4 and 5) which extend through seat 120 into portion112 of plate 46. Seat 120 includes an upwardly facing seat surface 122and a downwardly facing surface 124 on the opposite side of the seat.The seat may thus be easily removed and replaced to permit machining ofsurface 122 if necessary.

Valve member 74, the structure associated with plate 46 adjacent thevalve member and valve seat 120 and its associated structure arecollectively referred to herein as a pilot valve. The pilot valveoperates generally as described in connection with U.S. Pat. No.3,856,043 to Feild et al., such being submitted to the U.S. Patent andTrademark Office herewith and incorporated herein by reference. Ageneralized description of the operation of the pilot valve inconjunction with the operation of valve 10 is provided hereinafter.

The space between working face 105 and seat surface 122 is referred toherein as a transversely wedge-shaped annular space when the valvemember is abutted against the seat surface. The annular space which isdefined on its radially inner side by a cylinder which is coaxial withand of equal diameter to bore 88 and on its radially outer side by theradially inner surface of counterbore 114 is referred to herein as afluid pressure chamber and as a pilot valve inlet. Also comprising thefluid pressure chamber are bores 116, 118 and the space between thelower surface of plate 46 and the upwardly directed surfaces of aslidable valve member or a piston 126. The upwardly-directed surfaces ofpiston 126 are referred to herein as the piston upper side or end or asthe rear face of the piston.

Piston 126 is received in a radial bore 127, such being formed in middleportion 16 of valve body 12 and being coaxial therewith. Sealing meansor o-rings 129, 131 are sealingly engaged between the outer surface ofpiston 126 and the radially inner surface of bore 127. O-ring 129 isreferred to herein as a second o-ring.

Piston 126 includes a cavity or annular opening 128 formed therein whichdefines a portion of the fluid pressure chamber A post 130 defines theradially inner side of the annular cavity. A spring 132, such being alsoreferred to herein as biasing means, is disposed between a lower surfaceof valve seat 120 and an upper surface of piston 126 and is receivedover post 130. Spring 130 thus biases the piston downwardly.

An annular space 134 is defined by a groove formed on the radially outersurface of piston 126. A first bore 136 provides fluid communicationbetween port 58 and space 134 and a second bore 138 provides fluidcommunication between space 134 and the fluid pressure chamber.

Port 58, bore 130, space 134 and bore 138 are referred to hereincollectively as means for communicating pressurized fluid to the uppersurface of the piston or to the fluid pressure chamber.

Piston 126 includes a working face 144, such being also referred toherein as a lower piston surface. Working face 144 opposes a seatsurface or working face 146 which is formed on the upwardly-directedsurface of a valve seat or annular member 148. Annular member 148includes therein an axial orifice or bore 149 having an upper end influid communication with working face 146 and a lower end in fluidcommunication with the lower surface of annular member 148.

In the instant embodiment of the invention, working face 146 issubstantially flat while working face 144 is at an angle thereto thusforming a transversely wedged-shaped annular space between the twoworking faces when piston 126 abuts against member 148. In the instantembodiment of the invention the angle is approximately three (3)degrees, thirty-eight (38) minutes. As used herein the term "taper" inreference to the relative positions of working faces 144, 146 mightinclude curved working faces as well as flat faces with the "taper" or"wedge" aspect relating to an increase in the distance between the facesas the radially outer portions of the working faces are approached.

The relative positions of working faces 144, 146 are referred to hereinas means for confining pressure drop to a location closely adjacent theorifice.

Annular member 148 is received within a substantially cylindrical cavity150 formed in body 12. A pair of threaded inlet means or bores 152, 154are coaxial with one another on opposite sides of middle portion 16 ofvalve body 12.

A threaded outlet bore 156 is coaxial with body 12 and with bore 149 andannular member 148. Bores 149, 156 are referred to herein collectivelyas outlet means.

The cross-sectional area of the annular space between the radially outersurface of member 148 and the radially inner surface of cavity 150 isequal to approximately one half of the cross-sectional area of each ofinlet bores 152, 154.

Finishing now the description of the structure in FIG. 3, an annularflow restriction 158 is defined at its upper end by a break 160 in body12. Flow restriction 158 is also defined between a radially outersurface 161 on member 148 and the radially inner surface of cavity 150.The restriction is annular in shape, and as will later be more fullyexplained comprises an entrance to a fluid flow path and is alsoreferred to herein as an annular opening or space. Ideally thecross-sectional area of this space is preferably in the range of 50% to200%, depending on the flow rate, of the minimum cross-sectional area ofbore 149 for reasons for which will be more fully explained inconnection with the description of the operation of valve 10hereinafter.

Structure which has been previously identified in FIGS. 1-3 retains thesame numeral in FIG. 4. It should be noted that bores 40, 42 have beenshifted into the plane of FIG. 4 from the view of FIG. 2 for thepurposes of illustration only.

Consideration will now be given to the structure of cartridge valveassembly 38 in FIG. 4. Included therein is a cartridge valve body 162.The valve body includes a generally tubular outer element 164 and agenerally tubular inner element (such being also referred to herein as acylindrical element) or flush nut 166.

Element 164 is received in a bore 168 formed in upper portion 14 coaxialwith stub 28. Element 164 includes a circular portion which extends tothe right of stub 28 in FIG. 4 and which includes therein a plurality ofradial bores, like bore 40, disposed on the radially outer surfacethereof. These bores are used to receive prongs which extend from awrench (not shown) for threadably engaging and disengaging element 164with a threaded connection 170. One or more set screws, like set screw171, are received through threaded bores in element 164 and abut againstthe radially outer surface of stub 28 to lock element 164 againstrotation.

A second threaded connection 172 is formed between flush nut 166 andtubular element 164. The bores, like bore 42, on the radially outersurface of that portion of flush nut 166 which extends to the right oftubular element 164 accommodate a wrench (not shown) to enable rotatingflush nut 166 to engage and disengage threaded connection 172. Theleftmost surface 174 of flush nut 166 is firmly abutted against ashoulder 175 formed on the radially inner surface of element 164.

An elongate stem 176, such also being referred to herein as a secondvalve member, is coaxially engaged via threaded connection 178 withflush nut 166. As will later be more fully described, stem 176 isaxially positionable relative to flush nut 166, under the action ofthreaded connection 178, when stem 176 is rotated. Lock nut 44 may thenbe tightened onto stem 176 until the same is engaged against therightmost surface of flush nut 166 thereby locking stem 176 relative tothe flush nut.

Stem 176 includes thereon a piston portion 180. Portion 180 is sealinglyengaged with a coaxial bore 182 formed in tubular element 164. Thatportion of bore 182 to the left of the o-ring received about piston 180is referred to herein as an internal cavity. A first valve member 184makes up the leftmost end of tubular element 164 and includes thereon asubstantially flat working face 186. Working face 186 is substantiallyparallel to a second working face 188 formed on the leftmost end ofpiston 180. A pair of opposed radial bores 190, 191 are formed betweenbore 182 and the radially outer surface of tubular element 164. Each ofbores 190, 191 may be referred to herein as a first bore. Bores 190, 191are opposite an annular groove 193 formed about the circumference ofelement 164.

A pin 195 is fixedly received in a radial bore formed through element164. The pin extends into bore 182 as shown. As will later be described,pin 195 provides an important safety feature.

An axial bore 192, such being referred to herein as a second bore, isformed coaxially through first valve member 184 and communicates with abore 194 formed in upper portion 14. Bore 194 provides communicationbetween bore 192 and space 134. Piston 126 includes a bore 198 betweenannular opening 128, which comprises the fluid pressure chamber, andspace 134.

A radial groove 200 is milled in upper portion 14 on one side of bore168. Groove 200 enables fluid communication between flow restriction 158(in FIG. 3), via bore 202, and the space between working faces 186, 188via bores 190, 191.

Turning now to FIG. 6, plug 30, such being previously identified inFIGS. 1 and 2, is engaged in a bore 204 formed coaxially with stub 26via threaded connection 206. Plug 30 has the rightmost end thereofseated against the end of bore 204. An o-ring 208 seals the centralportion of the end of plug 30 from fluid communication with the outerend portion and sides of the plug. A bore 210 formed in upper portion 14of the valve body communicates at one end with space 134 and has theother end thereof sealed against the central portion of the plug end.Thus, in the configuration shown in FIG. 6, there can be no flow throughbore 210.

A pair of bores 212, 214 are formed in valve body 12. Bores 212, 214 arereferred to herein as means for communicating fluid pressure from theoutlet bore to the fluid pressure chamber. Bore 214 communicates at oneend with outlet bore 156 and at its other end with the lower end of bore212. The upper end of bore 212 communicates with a groove 216 which ismilled in upper portion 14 of the valve body inside bore 204. Groove 216thus communicates at one end with the upper end of bore 212 and at theother end with bore 204 in which plug 30 is received. O-ring 208 thusseals groove 216 and bore 210 from one another.

A second o-ring 218 seals between bore 204 and plug 30 around thecircumference of the plug. A lock screw 220 is threadably engaged in abore in the plug as shown thus locking plug 30 against rotation.

Turning now to FIGS. 7-11, consideration will be given to some of thedifferent configurations in which valve 10 may operate and the manner ofoperation of each configuration.

In the relief/regulator mode, the valve is configured as shown in FIGS.7 and 11.

In FIG. 7, ports 58, 60 are plugged as shown and a line 222 providesfluid communication between port 56 and port 62. When the valve is soconfigured, as will later be described, it operates in arelief/regulator mode by venting fluid via output bore 156 from a pipeconnected to inlet bores 152, 154 in order to prevent fluid pressure inthe line connected to bores 152, 154 from rising above a preselectedlevel.

FIGS. 10 and 11 show the two configurations in which the valve may beplaced by varying the positions of plug 30 and cartridge 38. In FIG. 10cartridge 38 is received in bore 204 and plug 30 is received in bore168. In FIG. 11 the positions of the cartridge and plug are reversed andare as shown for cartridge 38 in FIGS. 4 and 5 and for plug 30 in FIG.6. In the relief/regulator mode, the valve is configured as shown inFIG. 11 (and FIG. 7).

In the relief/regulator mode, fluid pressure in inlet bores 152, 154 ismaintained at a predetermined level and fluid is vented via outlet bore156 to a tank (not shown) in varying amounts in order to so maintain thepressure. It should be appreciated that in the relief/regulator mode thevalve can be connected at a terminal end of a pipe via one of inletbores 152, 154 and the other may be plugged. Two inlet bores areprovided for convenience to enable connections of additional valves ormeters or the like.

With reference also to FIGS. 3 and 4, initially piston 126 is in theposition shown in FIG. 3, i.e., spring 132 biases the piston against thesurface 146.

As fluid enters the annular space defined between the radially innersurface of cavity 150 and the radially outer surface of annular member148, under power of, e.g., a pump, the fluid divides substantiallyevenly around the annular member.

Because of the relatively small cross-sectional area of annular flowrestrictor 158 relative to the flow rate therethrough, the fluid issubstantially evenly distributed about valve seat 148 in annular space158. A flow rate and/or restriction cross-sectional area which will sodistribute the fluid can be easily determined by a person havingordinary skill in the art. As previously noted, the cross-sectional areaof restrictor 158 is preferably in the range of 50% to 200% of theminimum cross-sectional area of bore 149. For a given size ofcross-sectional area for restriction 158, an appropriate flow rate maybe determined by adjusting the rate until the fluid is so distributed.After the fluid flows through restriction 158, it enters the spacebetween working faces 144, 146. Restriction 158 thus preventspressurized fluid from approaching piston 126 from a single side therebyurging the piston sideways and causing increased wear and preventingappropriate piston movement. The fluid flows radially from the outercircumference of the working faces toward orifice 149. As the flowincreases, piston 126 is urged upwardly against the biasing force ofspring 132. When the upward pressure of the fluid beneath piston 126equals the downward biasing force of spring 132, upward piston movementstops while flow between the working faces and into orifice 149continues.

Referring now to FIG. 4, it can be seen that fluid in flow restrictor158 also flows into bore 202, groove 200, space 193 and bores 190, 191into the space between working faces 186, 188 of cartridge valve 38.

From the space between the working faces fluid flows into bores 192,194, space 134 and bore 198 into annular opening 128 which is incommunication with the entire upper surface of piston 126.

Because plug 30 is received in bore 204 as shown in FIG. 6, no flowoccurs in bores 214, 212, 210.

When the fluid pressure chamber above piston 126 is filled with fluid,pressure in the chamber begins to rise. Such fluid pressure iscommunicated via bores 116, 118 to the working face 105 on the lower endof valve member 74. When the pressure on working face 105 is sufficientto overcome the downward biasing force of spring 78 on valve member 74,the valve member moves upwardly and fluid is vented via bores 104, 106,102, port 56 and into line 222 which in turn vents the fluid via port 62to outlet bore 156 which, as will be recalled, is the flow path forfluid vented through valve 10 in order to prevent the pressure on inletbores 152, 154 from rising above a preselected level.

It can be seen that the downward biasing force of spring 78 determinesthe maximum pressure which can appear from the fluid chamber abovepiston 126. This downward force is adjustable by compressing anddecompressing the spring via nut 54. For a given position of nut 54 thepressure in the fluid pressure chamber will not rise above a pressurelevel determined by the spring force.

It can be seen that as pressure in the fluid pressure chamber begins torise, piston 126 begins to move downwardly as a result thereof. Whenvalve member 74 begins to vent fluid from the fluid pressure chamber,the pressure rises no further, because it cannot, and downward pistonmotion stops. The regulator is now operating in a steady state conditionwith the pressure on the upper side of the piston being slightly lessthan the pressure on the downward-facing side of the piston. This is sobecause there is less pressure on face 144 above orifice 149 (which maybe at atmospheric pressure) thereby providing only an annular area onthe lower side of the piston against which full fluid pressure can beexerted whereas the entire upper surface of the piston is exposed topressure in the fluid pressure chamber.

It should be noted that the speed at which valve 10 goes from initialfluid flow to steady state operation may be varied by adjustingcartridge valve assembly 38. In order to, e.g., increase the flow ratethrough cartidge valve assembly 38, it is changed from the configurationshown in FIG. 4 to that shown in FIG. 5. Such change may be achieved inone of several ways.

Firstly, assuming no fluid flow through through valve 10, lock screw 171is loosened and the previously-referred to wrench (not shown) may beengaged with the bores, like bore 40, about the circumference of tubularelement 164. The wrench is used to unthread threaded connection 170thereby removing tubular element 164 and the structure carried thereon(namely flush nut 166, stem 176 and lock nut 44) from bore 168.Thereafter lock nut 44 is loosened from the position shown in FIG. 4 toenable axial rotation of stem 176 via threaded connection 178.Alternatively, it may be desirable to loosen lock nut 44 prior toremoving tubular element 164 from bore 168. In any event, once stem 176may be moved along threaded connection 178, a thickness gauge may beinserted between working faces 186, 188 via bore 190 or bore 191. Stem176 may be turned in a direction which moves working face 188 towardworking face 186 until the thickness gauge is touching both faces.Thereafter lock nut 44 is tightened to fix stem 176 relative to tubularelement 162.

At higher flows through cartridge valve assembly 38, valve 10 achievessteady state operation more quickly than at lower flows. However, higherflows through valve assembly 38 use more pressurized fluid therebyexpending more energy. It is therefore desirable to use lower flow ratesunless the particular application requires that the valve rapidly arriveat steady state operation requiring use of higher flow rates throughvalve assembly 38.

It is to be appreciated that cartridge valve assembly 38 may becalibrated to correlate a given axial position of stem 176 relative toflush nut 162 with a given cross-sectional flow area between the workingfaces. The minimum cross-sectional flow area in valve assembly 38 isequal to the surface area of a cylinder having the diameter of bore 192and a height equal to the distance between working faces 186, 188.

After cartridge valve assembly 38 is so adjusted, the same can bereinserted into bore 168 by making threaded connection 170 until theleftmost end of tubular element 164 is flushly abutted against thebottom of bore 168.

If during operation of the valve it is desirable to flush the spacebetween or around working faces 186, 188 to remove any scale, dirt orthe like which may have accumulated, the previously-referred to wrenchmay be inserted in the bores, like bore 42, in flush nut 166 and thesame may be unthreaded from threaded connection 172. This withdraws stem176 relative to tubular element 164 thus separating the working faces ofthe cartridge valve and permitting a temporarily increased flowtherebetween. Such flow flushes any grit, scale or the like from betweenand around the working faces.

After the valve is so flushed, flush nut 166 is axially rotated therebyreturning the same to the position shown in FIG. 4, i.e., surface 174 isflushly abutted against shoulder 175 as shown in FIGS. 4 and 5. Whenthis position is resumed, the previously-calibrated spacing betweenworking faces 186, 188 is restored.

In a situation in which the calibration of cartridge valve assembly 38is not critical, the same may be adjusted without removing tubularportion 164 and may even be adjusted during flow through the valve. Suchis achieved by loosening lock nut 44 and using the slot on the end ofstem 176 to vary the axial position of the stem relative to flush nut166 until the desired flow through the cartridge valve assembly isachieved. Flow through valve assembly 38 may be monitored by measuringthe flow from port 56.

Pin 195 prevents removal of stem 176 either by unthreading the same fromthe flush nut or by unthreading flush nut 166 from threaded connection172. In either case, the rear of piston 180 strikes the pin and preventsfurther withdrawl. This serves as a safety feature to prevent leakage,which might occur in the form of an extremely high pressure fluid streamwhen the valve is regulating high pressures, during adjustment ofcartridge valve assembly 38 while fluid is flowing in valve 10.

Returning again to consideration of the overall operation of valve 10,it will be recalled that when in the relief/regulator mode, valve 10prevents fluid pressure in inlet bores 152, 154 (and in any pipesconnected thereto) from rising above a predetermined level. When valve10 is so operating in steady state condition, fluid is continuouslyvented via valve member 74 and port 56 in order to prevent the pressurein the fluid pressure chamber above piston 126 from rising above thepreselected level determined by the downward biasing force exerted byspring 78.

The maximum flow achieveable through bore 192 in cartridge valveassembly 38 is less than that achieveable through bores 104, 106 ofvalve member 74. Thus, even under the highest possible flow rates andpressures, pressure in the fluid pressure chamber does not rise abovethat determined by spring 78. If greater flow were achieveable throughcartridge valve assembly 38 than through the pilot valve, thepossibility exists that pressure in the pressure chamber could riseabove the pressure beneath piston 126 thus slamming the same shut.

It can be seen that in steady state operation, there is no pressuredifferential across o-ring 129 because both sides of o-ring 129 areexposed to the pressure in the fluid pressure chamber. O-ring 129 servesto center piston 126 to prevent metal-to-metal contact.

There is only a slight pressure drop across o-ring 131. In testsconducted with a valve constructed as shown in FIG. 3, when the pressurein inlet bores 152, 154 was 350 psi, pressure on the top of the pistonwas 323 psi. With adjustment nut 54 set to regulate inlet pressure at3000 psi, the pressure on the top of the piston was 2838 psi thusputting only 162 psi differential across o-ring 131. The pressure on thetop of the piston is typically 4% to 8% less than that beneath thepiston for all operating pressures.

In the event of a sudden pressure surge, e.g., in the fluid provided toinlet bore 152, piston 126 is forced upwardly thereby compressing thefluid in the fluid pressure chamber above the piston and forcing valvemember 74 upwardly. Upward movement of member 74 vents fluid from thepressure chamber and prevents an increase in the pressure thereof. Suchpressure relief in the pressure chamber occurs before the increase influid pressure is communicated to the pressure chamber via cartridgevalve assembly 38. This exceptionally fast response to pressure changesis a result of the inlet of the pilot valve, which includes member 74,being received in the fluid pressure chamber and of the operatingcharacteristics of the pilot valve.

It should be appreciated that in steady state operation the valve canvary the flow through orifice 149 in order to prevent the pressure ininlet 152 from rising above the level preselected by spring 78 withrelatively small movements of piston 126. In fact, o-rings 129, 131,after the valve is in steady state operating condition, typically do notwipe the radially inner surface of the bore in which they are receivedbut merely flex as piston 126 moves slightly upwardly and downwardly inorder to maintain pressure. This is a result of the cross-sectional flowarea between working faces 144, 146 being substantially variable byrelatively small movements of piston 126. The minimum cross-sectionalarea between faces 144, 146 is determined by calculating the radiallyouter surface area of a cylinder having a diameter equal to bore 149 atits intersection with working face 146 and a height equal to thedistance between working faces 144, 146 at the intersection of bore 149with working face 146. Relatively small movements of piston 126significantly change the cross-sectional flow area thereby enabling awide range of pressure regulation with relatively small pistonmovements.

Valve 10 may typically be used on a line having other valves or fluidiccomponents thereon which, in operation, divert flow from valve 10. Asflow is diverted, it can be seen that the total flow between workingfaces 144, 146 decreases thereby permitting piston 126 to movedownwardly. Such downward movement reduces the flow through orifice 149thereby maintaining pressure in inlet bore 152 at the preselected value.As flow through other devices continues to divert flow away from valve10, working face 144 approaches working face 146.

The relief/regulator valve of the invention provides a very flat flowversus pressure curve. In other words, the regulator prevents pressurefrom rising above a preselected level at the inlet bores for a very widerange of flows through orifice 149 from the very highest down to thevery lowest flows thus producing a substantially square flow versuspressure curve for the valve.

Under certain conditions of flow rate and compression of spring 78,piston 126, best viewed in FIG. 4, will be positioned substantiallyupwardly from its lower-most position (which is shown in FIG. 4) thusproviding a substantial gap between working faces 144, 146. Under othersuch conditions, piston 126 operates in steady state condition onlyslightly above annular member 148 with working faces 144, 146 beingrelatively close to one another.

When piston 126 is operating so that faces 144, 146 are relatively closeto one another, the degree of taper between the working faces iscritical. If the taper, for substantially flat faces as in the instantembodiment of the invention, is less than about two (2) degrees, twenty(20) minutes, the pressure between working faces 144, 146 may drop tothe point where the pressure above piston 126 causes the piston to slamshut, i.e., piston 126 abuts against annular member 148 thus preventingpressure regulation as described above.

The pressure on the radially inner peripheries of working faces 144, 146may approach atmospheric pressure, e.g., when the pressure in bore 149which is vented to a tank, while the pressure on the radially outerperipheries of working faces 144, 146 is at the regulated pressuredetermined by the compression setting for spring 78. The valve canregulate pressures as high as 5,000 p.s.i. and higher, thus producing asubstantial pressure drop between the radially outer and innerperipheries of working faces 144, 146.

In the case of, e.g., substantially parallel working faces, thispressure drop tends to be evenly distributed between bore 149 and theradially outer peripheries of working faces 144, 146 as the workingfaces approach one another. When such occurs, the pressure beneathpiston 126 is substantially lowered, thus causing the pressure on top ofthe piston to slam the same shut as described above.

In order to maintain the pressure drop which occurs between the radiallyouter peripheries of working faces 144, 146 and the radially innerperipheries thereof closely adjacent the radially inner peripheries(i.e., adjacent bore 149), the working faces must be further apart atthe radially outer peripheries thereof than at the radially innerperipheries. In the case of substantially flat working faces as in theinstant embodiment of the invention, it has been discovered thatsufficient spacing between the faces occurs if the working faces assumean angle of at least approximately two (2) degrees, twenty (20) minutesto one another.

When the pressure drop occurs adjacent bore 149 rather than at the outerperipheries of the working faces, the lower pressure appears beneath asmaller area at piston 126, i.e., that adjacent bore 149, therebycreating less downward force than if the pressure drop was evenlydistributed between the radially outer peripheries of the working facesand the radially inner peripheries thereof. It is to be appreciated thatthe degree of angle, at least in the lower ranges of taper in accordancewith the invention, i.e., above approximately two (2) degrees, twenty(20) minutes, affects the distribution of the pressure drop beneath thepiston. Thus, changing the taper angle changes the downward force onpiston 126 for a given relative position of working faces 144, 146.

Alternatively, if the taper is too large, e.g., on the order ofapproximately 25° or larger, the valve begins acting as a needle valvethus causing turbulent flow and the resultant noise and wear of workingfaces 144, 146 adjacent the intersection of orifice 149 with workingface 146. Thus, the ideal angle of taper between working faces 144, 146is between about two degrees, twenty-minutes and about twenty fivedegrees.

Consideration will now be given to the operation of valve 10 in areducing valve configuration, as shown in FIGS. 8 and 11.

In FIG. 8, ports 58, 60, 62 are plugged as is inlet bore 154. Port 56 isconnected via a line 224 to a fluid tank 226. A pipe carrying fluid isconnected to inlet bore 152 with the fluid exiting the valve via a pipeconnected to outlet bore 156.

In FIG. 11, plug 30 and cartridge valve assembly 38 are positioned asshown in FIGS. 4-6.

When configured as shown in FIGS. 8 and 11, the valve is inserted in aflow line with input flow applied to inlet bore 152 and output flowflowing from outlet bore 156. In this configuration the valve reducesthe pressure appearing at inlet 152 to a lower pressure on outlet 156.In this configuration, the internal components of valve 10 functionessentially as described in connection with the relief/regulatorconfiguration of FIGS. 7 and 11.

As fluid enters inlet 152 initially, piston 126 is urged upwardly untilthe pressure in the fluid pressure chamber above the piston beginsrising at which point piston 126 begins to lower until the upward anddownward pressures on the piston are equalized. Valve 10 then beginssteady state pressure-reducing operation. It can be seen that if thepressure at inlet bore 152 tries to increase, the pressure increase iscommunicated to working face 144 on the piston which urges the sameupwardly thereby increasing flow through orifice 149 and preventing thepressure at inlet bore 152 from rising. As in the case with therelief/regulator mode, pressure increases in the fluid pressure chamberabove piston 126 which are a result either of upward piston movement orof pressure communicated to the piston chamber via cartridge valve 38are limited by valve member 74 which vents fluid via line 224 to tank226. The configuration of FIGS. 8 and 11 thus provides a pressurereducing valve which prevents pressure at the inlet thereof from risingabove a preselected level.

Another pressure reducing valve configuration is shown in FIGS. 8 and10. In order to change from the previously just described configurationof FIG. 8 and 11, valve assembly 38 is switched with plug 30 to producethe configuration of FIG. 10.

As in the case of the description in connection with the configurationof FIGS. 8 and 11, valve 10 is a pressure reducing valve in a pipelinehaving a flow entrance at inlet 152 and a flow outlet at outlet 156. Itcan be seen by examining FIG. 10 that fluid pressure from outlet 156 iscommunicated via bores 214, 212 and cartridge valve 38, now received inbore 204 (in FIG. 6), to the fluid pressure chamber above the piston. Ashas been previously described herein, depending upon the adjustment ofvalve assembly 38, the fluid pressure chamber fills with fluid afterflow through the valve begins, the fill time depending upon theadjustment of the cartridge valve. When flow first begins, piston 126 isurged upwardly until the fluid pressure chamber fills thereby causingpressure in the chamber to increase. The pressure increase beginsmovement of piston 126 downwardly until the forces exerted on both sidesof the piston are balanced and steady state operation begins.

In this configuration, valve 10 reduces pressure responsive to thedownstream pressure which is applied to the top of piston 126.

Turning now to the configuration shown in FIG. 9, ports 60, 62 areplugged and port 56 is again connected via line 224 to tank 226. Anexternal source of pressurized fluid 228 is connected via a line 230 anda flow restricting valve 232 to port 58. In the instant embodiment ofthe invention valve 232 is constructed in accordance with the flowrestricting valve shown in FIGS. 14-16 and described hereinafter. Inthis configuration, the valve may be operated as a pressure reducingvalve or in a relief/regulator mode.

When configured as in FIG. 9, a remote source of pressurized fluid 228is utilized to control pressure in the fluid pressure chamber on top ofpiston 126 rather than sampling the pressures appearing at the inlet oroutlet bores of the valve. When so used, two plugs, like plug 30, arescrewed into bores 168, 204. The device of FIG. 9 may be used either asa relief/regulator or as a pressure reducing valve in a flow line withflow input to the valve appearing at inlet bore 152 and flow output atbore 156.

The configuration of FIG. 9 operates as described in connection with thepreviously described relief/regulator and pressure reducing modes exceptthat the pressure sensed above piston 126 is determined by the pressureof pressurized fluid 228 rather than by the inlet or outlet pressures.When so configured, valve member 74 may be set to open at some pressureslightly above that of pressurized fluid 228 thereby providing a backupsafety pressure relief.

Turning now to FIGS. 12-16, consideration will given to a secondembodiment of the invention. Indicated generally at 234 is a valveconstructed in accordance with the instant invention. Structure whichhas been previously identified in connection with the embodiment ofFIGS. 1 and 2 bears the same numeral in FIGS. 12 and 13. Generallyspeaking, the only difference in valve 10 and valve 234 is that valve234 includes an external valve assembly, indicated generally at 236,which may be connected via lines, as hereinafter described, with ports56, 58, 60, 62 to cooperate with the remainder of valve 234 in the samemanner that cartridge valve assembly 38 cooperates with the remainder ofvalve 10.

Valve 234 also includes a cap 238 which is removably mounted on the topof spring shell 50 for covering and protecting adjustment nut 54 asshown.

Valve assembly 236 includes therein a valve body 240 having asubstantially cylindrical element or flush nut 242 threadedly connectedthereto via a connection 244 (in FIG. 14). An elongate stem 246, suchalso being referred to herein as a second valve member, is threadablyengaged via connection 248 with the flush nut. A lock nut 249 locks stem246 relative to flush nut 242 as shown in FIG. 14.

Valve body 240 includes therein an inlet bore 250 such being referred toherein as a first bore, and an outlet bore 252, such being referred toherein as a second bore. Each bore intersects an internal cavity 254formed in the valve body. Another bore 256 may be plugged duringoperation of valve 236 or may be used to flush valve 236 when fluidflows therethrough. Cavity 254 includes therein a substantiallycylindrical valve member 258 having a working face 260 formed thereon.Stem 246 is substantially the same as valve stem 176 in FIG. 4 and alsoincludes a working face 262 at the lower end thereof. A retainer ring264 is received in a groove formed on a radially inner surface of valvebody 240 to prevent removal of flush nut 242 when fluid is flowingthrough the valve assembly. A downward facing shoulder 266 likewiseprevents unthreading of stem 246 from the flush nut while the valveassembly is operating.

Valve assembly 236 is mounted on a plate 268 which in turn is mounted onplate 46 via bolts 270, 272.

In operation, lines (not shown) may be connected to ports 250, 252 invalve assembly 236 in order to interconnect the same with the remainderof valve 234. When, for example, it is desired to configure the valve asa relief/regulator, port 56 is connected by a line to port 62, port 60is connected to bore 250 in valve assembly 236 and bore 252 on the valveassembly is connected to port 58. It can thus be seen that fluid flowoccurs from inlet bore 152 into flow restriction 158, from thence toport 60, into valve assembly 236 via bore 250, out of the valve assemblyvia bore 252 and back to the valve body via port 58. The operation isthus the same as that described in connection with the FIGS. 7 and 11relief/regulator.

With port 62 plugged and port 56 drained to a tank, as shown in FIG. 8,and with valve assembly 236 connected between ports 56, 60 as describedabove, the valve is in configuration for connection as a pressurereducing valve with pressure being applied from inlet bore 152 to thefluid pressure chamber above piston 126. Valve 234 thus operates in thesame manner as described in connection with the FIG. 8 and 11 operationof valve 10.

Alternatively, valve 234 may be configured as a pressure reducing valvewith the downstream pressure applied to the upper surface of piston 126in the same fashion as described in connection with the FIGS. 8 and 10embodiment of valve 10. This is accomplished by again draining port 56to a tank and by plugging port 60. A line is connected from port 62 tobore 250 of valve assembly 236 and another line is connected from bore252 of the valve assembly to port 58 thereby applying pressure appearingat outlet bore 156, via valve assembly 236, to the fluid pressurechamber above piston 126.

Finally, an external source of pressure, as described in connection withthe embodiment of FIG. 9, may be connected to port 58. With port 56connected to port 62 (or to a tank) and port 60 plugged, the valve maybe used as a relief/regulator. Valve 234 may be used as a pressurereducing valve with port 56 supplied to the tank, port 60 plugged (orconnected to a pressure gauge) and port 62 plugged.

When so configured, valve 234 may be operated as a relief/regulator orpressure reducing valve as described in connection with the FIG. 9configuration of valve 10.

Turning now to FIGS. 17-19, consideration will be given to a thirdembodiment of the invention. Indicated generally at 310 in FIG. 17 is aflow control valve constructed in accordance with the instant invention.Valve 310 includes a tubular housing 312 having a bore 314 formedtherein. Housing 312 includes inlet means or inlet 316, suchcommunicating with the interior of bore 314 via bore 318. Inlet 316includes a set of radially inner threads 320 for interconnecting thesame to a pipe (not shown) for providing fluid from the pipe into bore314.

Housing 312 further includes an outlet bore 322 which also includes aradially inner set of threads 324 for connecting outlet bore 322 toanother pipe (also not shown) for transmitting fluid from the interiorof bore 314 away from the valve

Generally speaking, valve 310 is used as a flow control valve in apipeline having flow into inlet 316, through bore 314 and out bore 322.As will later become apparent herein, valve 310 may be adjusted tovariably restrict the flow of fluid in the pipeline.

An adjustment nut 326 is threadably engaged with housing 312 at theupper end of bore 314 via a buttress threaded connection 328. Theadjustment nut is also referred to herein as a shaft moving means and asa cylindrical element. Nut 326 includes a substantially cylindricalupper portion 330 having a bore 332 which extends laterallytherethrough. A second bore (viewable in FIG. 19) extends through upperportion 330 substantially normal to bore 332. A bar or rod (not shown)may be inserted into or through bore 332 (or the other bore) in order tofacilitate turning nut 326.

Nut 326 further includes an intermediate cylindrical portion 333 havinga set of three parallel lines 334, 336, 338 scribed about thecircumference thereof thereby defining circles coaxial with cylindricalportion 333.

A lower cylindrical portion 340 includes a set of radially outer threadswhich interconnect with threads on the radially inner surface of theupper portion of bore 314 to form threaded connection 328.

An annular scale ring 342 is mounted on the upper surface of housing 312via screws 344, 346 (in FIG. 17) and screw 348 (in FIGS. 18 and 19).Slots as shown in ring 342 permit adjustment of the radial position ofthe scale ring. As can best be viewed in FIG. 18, ring 342 includesnumerals and lines printed thereon which, as will later be more fullydescribed, provide an indication of the adjustment of valve 310.

Upper cylindrical portion 330 of adjustment nut 326 includes a line 350scribed thereon which is used in conjunction with reading scale 342.

Lower cylindrical portion 340 includes a downward-facing axial bore 352.A pair of opposed annular bearing raceways 354, 356 are received in theupper portion of bore 352 and a thrust bearing, indicated generally at358, is received therebetween. Raceways 354, 356 and bearings 358 arereferred to herein collectively as bearing means. A substantially planardisk 360 is interposed between the lower surface of raceway 356 and theupper surface of a substantially cylindrical shaft 362.

An annular shaft guide 364 is received over the upper end of shaft 362.A retaining ring 366 is positioned against a lower surface of shaftguide 364 thereby maintaining the shaft guide, disk 360, raceways 354,356 and bearing 358 in position as shown. Retaining ring 366 is receivedin an annular groove formed on the radially inner surface of bore 352.

A retaining ring 368 is received in a groove 370 formed on the radiallyouter surface of shaft 362. Abutted against the underneath side of ring368 is a washer 372. Biasing means or spring 374 is compressed betweenwasher 372 and a disk 376. In the instant embodiment of the invention aplurality of commercially available spring washers comprise spring 374;however, a commercially available coil spring would work equally well.

Disk 376 includes a central bore 378 through which shaft 362 isreceived. A circular lip 380 includes a downward facing annular surfacewhich rests on an upward facing annular shoulder 382 formed in bore 314.A threaded collar 384 is engaged with the buttress threads found on theradially inner surface of bore 314 as shown. The collar is abuttedagainst disk 376 for maintaining the same in place. Bores, like bore 385are provided to enable a wrench (not shown) to engage collar 384 forthreadably engaging and disengaging the collar with bore 318. Aretaining ring 387 is received in a groove formed on the radially innersurface of bore 314 immediately above collar 384 thereby securing thesame in position. O-rings 386, 388 seal between the radially outersurface of disk 376 and the radially inner surface of bore 314 andbetween the radially inner surface of central bore 378 and the radiallyouter surface of shaft 362, respectively. Disk 376 and o-rings 386, 388are referred to herein collectively as sealing means.

A bore 389 is provided as a vent in housing 312 in the event of leakagethrough o-rings 386, 388.

A guide means or piston 390 is formed integrally with shaft 362 andincludes a substantially flat upper surface 392 and a tapered lowersurface 394. An annular raised portion 396 is formed integrally withshaft 362 and piston 390. When shaft 362 moves upwardly, portion 396abuts against the lowermost surface of disk 376 thereby maintainingfluid communication between surfaces 394, 392 via bores 398, 400. Ano-ring 402 is in sealing engagement between the radially outer surfaceof piston 390 and the radially inner surface of bore 314. O-ring 402serves as a guide for maintaining piston 390 and its associatedstructure substantially coaxial with housing 312. The radially outersurface of piston 390 which is closely adjacent the radially innersurface of bore 314 is referred to herein as a cylindrical portion ofpiston 390.

A shaft 404, such being coaxial with shaft 362, connects the lowerportion of piston 390 with the upper portion of a valve member 406.Shaft 404 is formed integrally with piston 390 and valve member 406.Valve member 406 includes a first lower side, such having a circularworking face 408 formed thereon, and a second upper side 410 whichincludes a tapered portion as shown. A cylindrical portion 412 of valvemember 406 defines an annular space 414 between the radially outersurface of cylindrical portion 412 and the radially inner surface ofbore 314.

Working face 408 includes a substantially flat circular portion 416centered thereon. As can be seen, the diameter of circular portion 416is slightly greater than that of an outlet orifice 418 which is formedin a valve member 420 (which is referred to herein as a first valvemember) beneath circular portion 416. A tapered portion 422 is definedbetween circular portion 416 and the radially outer edge of valve member406. Valve member 420 includes an upwardly directed substantially flatworking face 424. Working face 424 and circular portion 416 aresubstantially parallel to one another. In the instant embodiment of theinvention, the angle formed between tapered portion 422 and working face424 is approximately four (4) degrees, thirty-four (34) minutes.

It should be appreciated that the instant invention works equally wellif tapered portion 422 is formed on valve member 420 and the lower endof valve member 406 is substantially flat thus providing a taperedopening between the valve members about the circumference thereof whenthe same are abutted against one another.

When shaft 362 is urged downwardly, in a manner which will behereinafter described, valve member 406 abuts against valve member 420and working faces 408, 424 define therebetween a transverselysubstantially wedge-shaped space.

As described in connection with the embodiments of FIGS. 1-17, the taperangle must be sufficient so that most of the pressure drop beneath valvemember 406 occurs adjacent bore 418. Otherwise (i.e., if the pressuredrop is evenly distributed between the working faces) the valve may slamshut.

Outlet bore 322 and outlet orifice 418 are referred to hereincollectively as outlet means. An o-ring 426 seals between the radiallyouter surface of valve member 420, which is pressed into a counterbore428 in housing 312 as shown, to seal between the radially inner surfaceof the counterbore and the radially outer surface of the annular valvemember.

In operation, inlet 316 is connected to a pipe (not shown) whichprovides a flow of fluid into bore 314 via bore 318. Another pipe (alsonot shown) is connected to outlet bore 322 to provide a fluid flow pathfrom bore 314.

After fluid enters bore 314 via bore 318, it flows upwardly via bores398, 400 to the space between upper surface 392 of piston 390 and thelower surface of disk 376. Fluid also flows to the space between workingfaces 408, 424 via annular space 414. Even at high pressures and flowrates, annular space 414 substantially evenly distributes the fluidaround the outer peripheries of working faces 408, 424 therebypreventing lateral loading of valve member 406 and the structureassociated therewith.

Fluid flows between the working faces from the radially outerperipheries thereof toward orifice 418, into the orifice and into outletbore 322.

The degree to which valve 310 restricts the flow of fluid passingtherethrough can be changed by adjusting nut 326. If it is desired todecrease restriction of fluid flow, nut 326 is unscrewed from threadedconnection 328 thereby enabling upward movement of shaft 362. Sincespring 374 biases the shaft upwardly, as nut 326 moves upwardly thespring moves the shaft also upwardly while maintaining contact betweenthe upper surface of shaft 362 and disk 360. As the shaft raises, thespace between working faces 408, 424 increases thereby increasing flowthrough the valve.

Alternatively, nut 326 may be screwed downwardly in threaded connection328 by turning nut 326 in the opposite direction. Such urges the workingfaces toward one another thereby decreasing fluid flow through thevalve. Raceway 354 turns with nut 326 while raceway 356 remainsstationary. It can thus be seen that shaft 362 does not rotate as it israised and lowered responsive to turning nut 326.

When valve member 406 is operating so that faces 408, 424 are relativelyclose to one another, the degree of taper between the working faces iscritical. If the taper, for substantially flat faces as in the instantembodiment of the invention, is less than about two (2) degrees, twenty(20) minutes, the pressure between working faces 408, 424 may drop tothe point where the pressure above piston 406 causes the piston to slamshut, i.e., piston 406 abutts against working face 424 thus preventingflow through orifice 418.

Pressure on the radially inner peripheries of working faces 408, 424 mayapproach atmospheric pressure, i.e., the pressure in orifice 418, whilethe pressure on the radially outer peripheries of working faces 408, 424is at the pressure of the fluid provided to inlet 316. This fluidpressure may be as high as 5,000 p.s.i. and higher, thus producing asubstantial pressure drop between the radially outer and innerperipheries of working faces 408, 424.

In the case of, e.g., substantially parallel working faces, thispressure drop tends to be evenly distributed between orifice 418 and theradially outer peripheries of working faces 408, 424 as face 408approaches face 424. When such occurs, the pressure beneath valve member406 is substantially lower than that above it, thus causing the pressureon top of the piston to slam the same shut as described above.

In order to maintain the pressure drop which occurs between the radiallyouter peripheries of working faces 408, 424 and the radially innerperipheries thereof closely adjacent the radially inner peripheries(i.e., adjacent orifice 418), the working faces must be further apart atthe radially outer peripheries thereof than at the radially innerperipheries. In the case of substantially flat working faces as in theinstant embodiment of the invention, it has been discovered thatsufficient spacing between the faces occurs when the working facesassume an angle of at least approximately two (2) degrees, twenty (20)minutes to one another.

When the pressure drop occurs adjacent orifice 418 rather than at theouter peripheries of the working faces, the lowered pressure appearsbeneath a smaller area of valve member 406, i.e., that adjacent orifice418, thereby creating less downward force than if the pressure drop wasevenly distributed between the radially outer peripheries of the workingfaces and the radially inner peripheries thereof. It is to beappreciated that the degree of angle, at least in the lower ranges oftaper in accordance with the invention, e.g., between approximately two(2) degrees, twenty (20) minutes and approximately twenty-five (25)degrees, affects the distribution of the pressure drop beneath thepiston. Thus, changing the taper angle changes the downward force onvalve member 406 for a given relative position of working faces 408,424.

The sizes of valve member 406 and its associated structure are selectedso as to substantially balance the fluid pressure forces acting onpiston 390, valve member 406 and the shafts associated with each. Forexample, when the valve is in operative condition, i.e., filled withfluid flowing therethrough, fluid pressure acts upwardly on that portionof working face 408 which is over working face 424. Likewise, fluidpressure acts downwardly on tapered surface 410. Fluid pressure actsupwardly on tapered lowered surface 394 and, through bores 398, 400,acts downwardly on upper surface 392. Each of the foregoing surfaces aswell as the sizes of shaft 404, 362 and orifice 418 are selected so thatthe upward and downward forces acting on valve member 406 aresubstantially equal when fluid is in the valve.

Spring 374 is non-linear and creates a smaller upward force on shaft 362and the structure associated therewith when the spring is extended thanwhen the spring is compressed. Thus, when working faces 408, 424approach one another, and the pressure begins to drop beneath valvemember 406 as described above, the upward force in spring 372 is greatersince the spring is more compressed. The valve therefore tends tooperate in a substantially balanced condition.

A person having ordinary skill in the art can select appropriate pistonand shaft and spring tension to balance the upward and downward facesacting on valve member 406 and its associated structure therebyproviding a valve which is easily adjustable even at very high pressuresand flow rates. If the valve is to be used in a system which includeshigh downstream pressure, the same will act on circular portion 416.This can be taken into account in selecting piston and shaft sizes andtension on spring 374 substantially balance the upward and downwardfaces acting on valve member 406 thereby allowing easy valve adjustementeven in the presence of high downstream pressure.

Spring 374 prevents hysteresis which might be introduced by slack inthreaded connection 328 by maintaining upward pressure on shaft 362 andnut 326 at all times.

Scale ring 342 is calibrated so that line 350 indicates an equivalentorifice diameter on the scale ring. The equivalent orifice diameter iscalculated by determining the minimum cross sectional flow area throughvalve 310 and then converting the same to a diameter of a round orificewhich has the same cross sectional area.

The minimum cross sectional area through which flow occurs in valve 310is defined by the raidally outer surface of a cylinder having a diameterequal to orifice 418 and a height equal to the distance between centralportion 416 and working face 424. The radially outer surface area ofsuch a cylinder is the minimum cross sectional flow area through whichfluid in the valve flows. Relatively small rotational movement of nut326 significantly changes the cross-sectional flow area thereby enablinga wide range of flow control with relatively small movements of shaft362.

The numbers appearing on scale ring 342 are diameters of circular areas,in sixty-fourths of an inch, which are equal to the above-describedminimum cross sectional flow area in valve 310 when line 350 is alignedwith a selected number on scale 342. When line 334 only is visible abovescale 342 in the view of FIG. 17, line 350 is used to read off theradially outermost scale on ring 342, i.e., the scale from 0-34. Whenlines 334, 336 are both visible, the scale is read by aligning line 350with a number on the scale from 34-48 and when all of lines 334, 336,338 are visible, the valve is wide open.

Turning now to FIG. 20, indicated generally at 430 is a fourth valveconstructed in accordance with the instant invention. The structurewhich has been previously identified in FIG. 17-19 retains the samenumeral in FIG. 20. Shaft 362 is received in an axial bore 432 formed inlower cylindrical portion 340. A pair of bores, 434, 436 are formedtransversely to one another through the upper end of shaft 362 as shown.A pair of corresponding bores, one of which is bore 438, are formedtransversely through cylindrical portion 340 so that when shaft 362 isreceived within bore 432, bore 436 is coaxially aligned with bore 438and bore 434 is likewise coaxially aligned with an associated bore (notvisible) formed through cylindrical portion 340.

A pin 450 is received through bores 436, 438 and a pin 452 is receivedthrough bore 434 and the corresponding bore (not visible) formed throughcylindrical portion 340.

The pin and bore arrangement as described thus prevents rotational aswell as axial movement of shaft 362 relative to cylindrical portion 340.

The operation of the embodiment of the invention shown in FIG. 20 isessentially the same as that for FIGS. 17-19. However, in the embodimentof FIG. 20, shaft 362 is prevented from downward movement in the eventof a decrease in pressure beneath valve member 406 thus maintainingvalve member 106 in the position selected by rotation of cylindricalportion 340.

It is to be appreciated that additions and modifications may be made tothe instant embodiment of the invention without departing from thespirit thereof which is defined in the following claims.

What is claimed is:
 1. A fluid valve assembly comprising:a housing; afirst valve member mounted on said housing, said first valve memberhaving a working face; a second valve member received in said housingfor movement toward and away from said first valve member responsive topressure variations thereacross, said second valve member having aworking face on one side thereof directed toward said first valve memberand a rear face on the other side thereof; a centrally located orificeextending into one of said valve members from the working face thereof;inlet means formed in said housing for permitting a flow of fluid to alocation adjacent the outer peripheries of said working faces; means forcommunicating pressure on said second valve member working face to saidrear face; and a taper formed on at least one of said valve faces, saidworking faces forming an angle to one another of a size sufficient tosubstantially eliminate all pressure decrease between the outerperipheries of said working faces as said valve members approach oneanother when fluid is flowing therethrough.
 2. The fluid valve assemblyof claim 1 wherein said angle is between about two degrees, twentyminutes and about twenty-five degrees.
 3. The fluid valve assembly ofclaim 1 wherein said fluid valve assembly further comprises meansdisposed between said inlet means and the outer peripheries of saidworking faces for restricting the flow of fluid therebetween.
 4. Thefluid valve assembly of claim 3 wherein said restricting means comprisesan annular opening disposed about the outer peripheries of said workingfaces, said annular opening being defined by the outer surface of one ofsaid valve members and by an inner surface of said housing and having across-sectional area of less than approximately 200% of thecross-sectional area of said orifice.
 5. The fluid valve assembly ofclaim 4 wherein the cross-sectional area of said annular opening isgreater than approximately 50% of the cross-sectional area of saidorifice.
 6. A fluid valve assembly comprising:a housing; a first valvemember mounted on said housing, said first valve member having a workingface; a second valve member received in said housing for movement towardand away from said first valve member responsive to pressure variationsthereacross, said second valve member having a working face on one sidethereof directed toward said first valve member and a rear face on theother side thereof; a centrally located orifice extending into one ofsaid valve members from the working face thereof; inlet means formed insaid housing for permitting a flow of fluid to a location adjacent theouter peripheries of said working faces; means for communicatingpressure on said second valve member working face to said rear face; andmeans for confining substantially all pressure drop to a locationclosely adjacent said orifice for substantially all spaced-apartpositions of said working faces when said valve is in operativecondition, said confining means comprising a tapered configurationformed on the working face of at least one of said valve members todefine therebetween a transversely substantially wedge-shaped annularspace when the valve members abut one another.
 7. The fluid valveassembly of claim 6 wherein said confining means comprises a taperedconfiguration formed on the working face of at least one of said valvemembers to define therebetween a transversely substantially wedge-shapedannular space when the valve members abut one another.
 8. The fluidvalve assembly of claim 7 wherein said working faces are at an angle ofbetween about two degrees, twenty minutes and about twenty-five degrees.9. The fluid valve assembly of claim 6 wherein said fluid valve assemblyfurther comprises means disposed between said inlet means and the outerperipheries of said working faces for restricting the flow of fluidtherebetween.
 10. The fluid valve assembly of claim 9 wherein saidrestricting means comprises an annular opening disposed about the outerperipheries of said working faces, said annular opening being defined bythe outer surfaces of one of said valve members and by an inner surfaceof said housing and having a cross-sectional area of less thanapproximately 200% of the cross-sectional area of said orifice.
 11. Thefluid valve assembly of claim 10 wherein the cross-sectional area ofsaid annular opening is greater than approximately 50% of thecross-sectional area of said orifice.